I don’t mean to be rude, but those “snapping” pieces that you said cannot be done with regular manufacturing techniques do exist and are used extremely regularly in injection molded plastic parts. If you look up “plastic snaps” you can find entire design guidelines to create permanent or temporary snaps. Those guides are usually made for injection molded plastics so you have to change them slightly for 3d printing but they are very common

7:04 Such snap-in joints are actually manufacturable pretty good without 3D-printing. If your part doesn't have to be fully closed you can simply machine the recesses from the outside. Another option for fully closed surfaces would be injection molding with movable core pins. That's actually pretty standard in the industry and mainly limited by size. Another option would be milling or even EDM machining with special diamond shaped tools.

Honestly never thought about joining 2 pieces together without additional hardware/glue, or going for a woodworking like joint. Amazing design videos; you guys present these concepts in a super engaging way.

I have been in engineering design for 50 years + and at 69 years still going strong. I find 3D printing with a combination of laser amazingly useful for prototyping and congratulate you in your channel and videos. Unfortunately you will always get negative comments generally from those not involved in design and lacking in lateral mindedness which of course is essential in design. Your objective of giving inspirational ideas to others thus enabling them to make informed decisions is excellent. Well done...

I love how this channel features solutions that are genuinely useful but somehow so easy to understand. Anything that removes the absolute need for glue or screws is a pretty helpful design solution 😊

7:00 Worked as injected plastic part constructor, and yes, you can make such geometry in injection molding. With some small changes to geometry, like adding drafts to some faces. However, it would be expensive because you would need two very small sliders. And in traditional plastic injection molding, we would use proper positioning and proper hook (meaning, contact only on line, not surface to surface). I suspect it could be done in metal machining, but again, would be expensive, delicate work, with some changes in geometry, slot in corners would be rounded at least.

Great content and truly enjoy the re-education. Being in the injection mold industry for nearly 1/2 a century there is an ingrained way at which "we" see designing and producing parts. It's this type of content that truly helps to advance my (our) thinking. However, there are techniques and processes that may not be top of mind for making some geometries that have been referred to as "impossible to be made any other way" on this channel. In the last example with the internal grooves, fully enclosed, there is a method to release that geometry in production mold tooling... I developed it for molding internal hinges on the Motorola phones in the early 90's. This comment is meant only to inform and I realize has nothing to add to the 3d printing world. Please keep up the content as it is truly informative.

tapered dovetails for the win. They do it all and are easy to design. Just make the profile, project it to the other plane. Run an offset and finally a loft.

This type of content is gold. Thank you!

That snap together design at the end led me to rethink a snap together design that's been in my head and now physical. Interesting how a design can change so much in prototyping.

I really love these! I design for both printing (MJF, FDM and SLA) and for CNC and injection moulding. This is also good - but locking, flexing clips are very possible and very common in injection moulding. Sure, this exact execution is not but the concept is exactly the same. I think the lesson is that we can use a lot of the same thinking, but applying slightly different optimisations and exploiting different strengths is important.

Designing for the the process you'll be manufacturing with is a huge step that is often overlooked. Features like this can make or break the manufacturability of a part. Great video!

As a mechanical designer, this is an excellent explanation for anyone. Great video!

Just started a 20 hour print where I opted for bolts and encapsulated nuts… wish I would have seen this video first! Nice work!

Excellent job with this video. But the snap-in joints are typically called snap fits. They are actually used a lot with injection molded parts but if I need a semi-flexible yet strong part, their basic design has almost always been the answer, especially when 3D printing.

I sometimes use Lego Technic Pins to join 3D printed parts.

Thanks for giving your expertise out to the community, it’s people like you that push the industry forward.

I found this extremely helpful in thinking through different designs for joining. Thank you for sharing!

This one of your best videos for expanding my thoughts on 3d printing. I echo the person that said uploading your model would great. Keep up the good work!

I am working on a racing sim periphery and my main goal is the least amount of parts for ease of assembly. After about half a dozen iterations i managed to remove 80 % of the added joining hardware like bolts and nuts. This video showed me how to remove the last 20 %. Thank you so much.

For this type of content it would be sweet if you could upload f3d/step files somewhere so we can take a closer look in 3d or print them out at home.

Especially the spring design, but more generally whenever tension between parts is needed to hold the joint together, you're going to be fighting against creep - the property of the plastic to gradually deform over long periods of time under load. I would consider these designs non-starters for PLA or nylon and questionable for PETG. For ABS, ASA, PC, or PET they're great.

Very inspirational. I appreciate the amount of models produced for this vid

I recently discovered your channel/company. This type of content you share testifies how knowledgable you are with 3d printing

Nice! My 2 "go to" connectors are the v-style tab (like the i-style but with "wings" on to stop it easily pulling out or flexing / rotating) and the "click-in-style" as you demonstrate, basically what you find on bag straps and belts that needs to mate together

This video series is great! I want more!!!

Best design for additive manufacturing account on the KZfaq 🥳🥳🥳🥳🥰🥰🥰🥰 I've learned so much from your channel! Thanks 😘

needed a thin section joinery -> Slot for 2mm sheet metal strip is what i'm going to try :) Glued in with E6000 or Epoxy is the plan.

Great video. Please do more!

Very good examples in your video. You can change the fit (how much clearance or interference), but you aren’t changing the tolerances. Tolerance would be how accurate and repeatable your 3D printing is. A worn lead screw or bad bearings would open up (worsen) the tolerance that you can meet. Take a look at an engineering drawing some time and you’ll see the tolerances required to make that part. You choose the process (machining, surface grinding, EDM, etc) based on those required tolerances.

I run a 3D printing club for a CSU and the main question I get is how to put parts together after segmentation. I’ll add some of these to my non permanent and sliding joints section. Personally I always preferred dove tail joints. Great content

Incredible. I was thinking this morning I needed a better way to combine two parts and POW this shows up. Amazing timing! 🎉🎉🎉🎉🎉

Tolerances are the bane of my existence. Literally every figure I download to print uses a key and hole (tongue and slot, whatever), a square bump that fits into a square hole, and not one artist has bothered with tolerances so the parts don't fit together and I have to sit there filling down the keys to make them fit. Even then they don't seem to fit cleanly.

New to 3D printing, and have been brainstorming custom fasteners. I was thinking about an internal hole, with a slot on the edge that acts as a key slot. a tongue can only be inserted sideways, and then once inserted sideways, the part is twisted 90° (or more depending on design) to engage some kind of locking design on the inside, that prevents the part from being turned in reverse to allow the tongue to be removed via the key slot. Edit: imagine a grip fin ( 5:22 ) on the inside of a part that prevents twisting the part in the opposite direction once the grip fins are engaged within the body of the part.

I usually use conical or pyramidal pins for locating 3d printed parts against each other. One irregular trapezoid pyramid for a low-precision joint, two elliptical cones for a more precise flat glue plane, or three circular cones and one threaded insert and bolt for a removable kinematic mount. Aggressively tapered pin edges are easy to print, easy to sand to a precise mating distance for a one-off, and easy to adjust CAD to get a second copy to mate perfectly right off the bed. They also provide excellent glue surface area.

I borrowed the concept of cordless power tools, the way 20V batteries snap into the tool is quite clever. Although much more complex to design, I found it really good to make detachable parts (with and without a detach button). Think the main takeaway is how the edges of the slot are a sequence of chamfers. This allows for bigger and safer tolerances that will still create a snap that does not jiggle.

If you look at the geometry at timestamp 3:01, you can see that this isn't printable. Yes, you can print the 45 degree centre, but the extreme edges of the curved head would be printed in fresh air. Personally, I often design something as a whole shape, then draw a dovetail with say 60 degree sides for the join. The dovetail has nice fillets added to it. The dovetail is made as part of a cut for one side and then flipped over for the other side. The part has two Configurations, and you output the sides as separate .step files for printing. I've found that printing everything size for size results in a nice tight press fit. You get pretty much the same shrinkage on both halves, so it just works.

Love it. Thank you. I have just one issue with this, however: Snap joints have been around for quite a while in injection molding. The mold just needs an extra mechanism for each end - the male and the female. The additional mechanism does increase cost, however, and is SO much easier to do with FDM than IM. FDM makes the hidden snap joint a no-brainer.

I'm kind of surprised no one uses any Japanese wood joinery designs in 3d printing, they look awesome.

And than there are the 3D professor locking mechanical interlock, were you turn the mechanical 45 degree. Great walk-throug of the options 👍😀

If it doesn't need to look fancy I often just screw them together with M4 bolts + nuts. With a bit of tolerance testing you can print hexagon-shaped recesses into which you can pull the nut via the screw, super easy to design and durable.

Omg this is exactly what I was looking for for the past 2 weeks 😮

Brilliant. I'd never thought of snapping together joints. Thank you for the inspiration.

As far as the locking tabs go you forgot about the classic dovetail. The dovetail is simple, locks better than the square tongue, and tends to be a strong connection. Depending on what you're making sometimes dovetails can be a feature of interest in addition to a connecting feature.

I love the idea of printing the fastener along with the part in one piece. Even for 3D-printed parts, I rely heavily on bolts which require the use of heat seat inserts to give the plastic part threads. Bolted connections are great and strong, but adding the inserts is an additional manual operation that takes time, unlike the print-in-place options you showed here. I'm definitely going to try one of these in a design, thank you!

I like the subject of this video, usefull for designing

Well done !

Wow! 3D Printing is super interesting! snap-in joints are super innovative! Thank you so much for sharing!

Great video! Other videos talked in generalisations, but you actually showed it in Fusion. Thanks!

Female half can be a spherical cut as long as the cavity is more than 1/2 a sphere and the male half joint is the same percentage of a sphere (I like 5/8 of a sphere on both but 2/3 has worked for me as well) These are snap fittings, but once they are in, they are pretty well in there unless you really want to play with the tolerances.

Let's all agree that.... every solution has a 'tolerance' issue. So, selling one technique over another based on 'tolerance' can only be about 'how much tolerance' you'll need to work.

I'm just getting into 3d printing for functional prototypes and really value the material that you are sharing.

Good video overall but the thing you said cannot be machined is done all the time. Check out the EDM sinker (ram EDM) process. For the design in question, an electrode would come in to the pocket and jog over to do the erosion/machining. Snap fits are commonly molded as well. All expensive stuff though.

These snap-in joints are great and I have been adding them to my assemblies too. I found the snap-in joint can be cylindrical in order to snap into a circular hole, if one-degree-of-freedom rotation of two parts is required.

I enjoyed that. Thanks

Another one (depending on the application): Dowels. Even some 1.75 holes and trim some filament offcuts.

I love this content. Studying mechanical engineering, so learning this is useful. The locking tabs look a little bit fragile to me, so i probably would have made the tabs have a slight curve or a fin in the middle to be sure the tabs do not break or weaken with extended use.

It is actually possible to make this by traditional plastic molding because it is possible to make injection forms that has small moving parts. It is important to say that if you are using nylon or other types of plastic, that is very liquid under the molding process, there is some things you can do

A dovetail connection is easy to design and print. Hold great.

The best "adhesive" for any thermoplastic is the material itself. You can design the join so that you can weld it together with a soldering iron tempered to around 200°C. Of course you need to use soldering iron tips that you don't use for soldering lead.

My favorite one to make is angled dove tails. They are nice because you can sit them flush and it's still a simple geometry. Plus if you angle it then it only comes apart in that direction which could be hard to know or see if it is not facing out. The top will look like a triangle but really it's slanted

A cool case study would be designing tubes and ducts (I've seen your vents video - very inspiring by the way). I printed a filament "Y" splitter for a BL-X1C and noticed that most of the models are printed vertically, which results in layer lines perpendicular to the filament flow. So if your filament has a sharp end, and it finds an unruly layer line, it will get stuck. A solution could be to use a hexagonal profile and print the splitter flat so that the layer lines wouldn't be perpendicular to the filament path. In the case of other ducts or pipes, I believe you spoke about this in the vents video, but the layer lines if perpendicular to the flow can create turbulence which may be good if you want to avoid material deposition, or if they are aligned with the flow may help laminar flow for other applications.

Dovetails and flanged dovetails? This gaves pretty good new ideas for modeling

just found your channel and absolutely love your content. keep making detailed videos about functional 3d design. could listen to your videos all day.

I use a lot the good old dovetail joint, used since forever in woodworking. In prusa slicer it’s easy to add at slicing time.

Excellent video - very thought provoking - thank you !

Absolute chad, very nice explanations

I'm a carpenter I stick to what I know and worked for centuries, I just make a dove tail. it is less likely to have anything sapping when pulled on and when you make the slot a tiny bit further in the parts get pulled together tightly.

Thank you for videos! Engineering solutions that you provide is exceptional !

Thank you so much for sharing your experience, very much appreciated.

Amazing. I was just sitting down to design a two-part print that has to hang reliably at an angle. This has a bunch of great ideas and perfect timing. :-)

Very helpful content! Will try out in my future projects. Well made video as well, compact and clear, not a single second is wasted. You got a new subscriber!

I like dovetail clips, very useful for parts to be permanently glued and superior to T or H clips

Another great video. Love these breakdowns of design considerations!

@7:12 these can be machined and molded. its a complicated mold, but machining is pretty straight forward with a slight change.

Great video. Really anticipated a dovetail and more variaty of snaps from injection molding, but yea, really good video

Oddly enough, today I was working on car holder for my iPhone. Basically keeping the parts of an off-the-shelf system that work well, and replacing the clumsy and awful thing that actually grips my phone with something bespoke. I came up with a design that had a PETG plate that had a connector for an existing ball mount. And the phone would be held by a TPU grip which was basically a hull between the PETG plate and the phone itself. The hardest part: get the TPU grip to stick to the PETG plate.

Ive used something similar for a permant conection to a tslot. 2 nubs that flex in during insert, then expand back out once in.

Great again, thank you!

Super video as always

Absolutely loving these videos!

Thank you for these super-informative videos! I would love guidance on - thin features like those snaps: do you make their thickness in multiples of 0.4? 0.5 due to pancaking? - unsupported spans: I gather from a previous video that 20-25mm is the limit, is that right? - tolerancing for tongue-and-groove: I used to design for a Stratasys uPrint with dissolving supports (yech!) and there I would design line-to-line and it worked great every time. Same or different with y’all’s printers? 👆🏼 having all these kinds of things encapsulated in a document on your website might also be nice :-)

This was extremely helpful and informative. Thanks

Amazing content, so useful! Thank you for your service to the community

i love these kind of video, please keep going on.

Good timing, i'm trying to come up with joining solutions for something I've made so this is handy.

Looks like something to make in OpenSCAD when I get home. Great idea!

Thank you. It was just what i needed yo know. Sadly money is tight, but I've subscribed and commented to help you with what i can, as you have helped me.

I haven't actually designed joint parts like this, but my intuition tells me I wouldn't want the joints to be permanently attached to either of the pieces and rather be a piece of itself. If both joint parts have female recesses and you have a male-male joint, it may not be quite AS snug, but if something breaks, you only have to print another joint. I'd really like to know what your opinion on that is!

For one thing, you forgot the dovetail. also, you could put the tongue on both parts as well a the hole and print one upside down to remove the need for supports. I wish I did that on my stupidly big spool holder instead of relying on dovetails all of the way through. I used 0.15 for a tight fit, which would be fine if the fit was shorter but, had to resort to a hammer to put them together.

Godly video. Big thanks,

Hi, could you make a video on how we could make moving parts, like how we should think about moving parts, like i wanted to make a chapstick tube that spins, but i had no idea how to

Good content! Useful and different from a lot of the stuff out there. Keep it up!

Snap in joints are actually very readily available in manufacturing. Undercutting using t slot cutters and form tools is do able. Its just less apt to use verse more common alternatives, rather than impossible.

thank you

What gives the best strength for a functional print that needs to support weight?

I tried making a concrete mold, and tried making those snap-locking pieces like in the last part of the video, but failed miserably because I didn't leave much room for the parts to move around. Gonna have to redesign the parts now that I've seen a real example. Thanks.

Great Video as always! Would love to see a video on thread design for 3d printing. Different size and shape and strengths/weaknesses of the different designs

I've been using a simple 'lego' like style, which yes you have to figure out your tolerances initially but once dialled in is very robust

Great tips. Thank you!